OBJECTIVETo assess the significance of stroke volume variation (SVV) and intrathoracic blood volume index (ITBI) on the responsiveness to volume loading in mechanically ventilated canine with hemorrhagic shock.

METHODSHemorrhagic shock canine model was established with the modified Wiggers' method. The heart rate (HR), mean artery pressure (MAP), central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), intrathoracic blood volume index (ITBI) and stroke volume variation (SVV) were investigated by Swan-Ganz catheter or PiCCO monitor. Graded volume loading (VL) was performed. Successive responsive VLs were performed (increase in SV > 5% after VL) until continuous change in SV < 5% (unresponsive) was reached.

RESULTSFourteen canines were studied and a total of 134 VLs were performed. In 94 VLs, an increase in SV of more than 5% was reached. In the other 40 VLs, increase in SV was less than 5%. The change of HR, MAP, ITBI, SVV in responsive were more than those of unresponsive after VL. The change of CVP, PAWP in responsive were less than those of unresponsive. Significant correlation was found between DeltaSV after VL and the baseline values of ITBI, SVV. No correlation was found between DeltaSV and HR, MAP, CVP, PAWP. Significant correlations were also found between DeltaSV and DeltaCVP, DeltaPAWP, DeltaITBI, DeltaSVV after fluid loading. No correlation was found between DeltaSV and DeltaHR, DeltaMAP. By using receiver operating characteristic analysis, the area under the curve were 0.872 for SVV and 0.689 for ITBI, more than those of HR, MAP, CVP, PAWP statistically. As SVV value of 9.5% or more will predict an increase in the SV of at least 5% in response to a VL with a sensitivity of 92.6% and a specificity of 82.5%.

CONCLUSIONSSVV and ITBI were more useful indicators than CVP and PAWP on the assessment of responsiveness to volume loading. SVV as a functional preload parameter and for on-line monitoring may help to improve the hemodynamic management.

Animals ; Blood Volume ; physiology ; Blood Volume Determination ; methods ; Dogs ; Female ; Male ; Shock, Hemorrhagic ; diagnosis ; physiopathology ; Stroke Volume ; physiology

In this paper, we propose the construction of a fifth-order Windkessel model, and give complete mathematical solutions for this model. Utilizing the diastolic pulse wave analytical methods, we derived the parameters of the mathematical model. The parameters were further applied to estimate arterial compliance, blood flow inertia, peripheral resistance and other indices. With simulation tools we assess the validity of the model, and built a simulation circuit with the model parameters R, C and L. The model parameters were obtained from the high-order Windkessel model. The stroke volume of left ventricle is employed as the input of the simulation circuit. At the end of the circuit, the responding signal was gained. And it in turn was compared with the measured pulse waveform. The results show that the fifth-order Windkessel model is superior to the third-order Windkessel model in the pulse wave fitting and stability, and thus better reflects the role of microvessles in the circulatory system.
Algorithms ; Blood Vessels ; physiology ; Compliance ; Computer Simulation ; Humans ; Microcirculation ; physiology ; Models, Cardiovascular ; Stroke Volume ; physiology

Transfusion therapy has changed in the past several years, largely as a result of improved knowledge of the physIology of hypovolemia, development of plasma expenders and plastic blood-collection equipment, the possibility of blood mediated infection and also shortage of whole blood Supply. In Korea, the difficulty of getting blood is remarkably increasing recently. According to recent studies, the patient seems can undergo rapid loss of 1000 to 2000mL, or up to 40 percent of their blood volume without developing irreversible shock, and that blood pressure can be maintained by the administration of saline fluids, lactated Ringer solution being presently most in vogue. If there is further blood loss, it may be necessary to augument the bodys circulating hemoglobin, but this can be done by the administration of packed cells. During 1968 and 1970 at St. Mary's Hospital took place 6904 general anesthesia. Blood transfusion or these cases were analysed. In the past several years, we have tried to reduce the whole blood transfusion during surgery and to use lactated Ringer's solution and plasma expanders like hemaccel and macrodex, etc. In this review there was significant change in intraoperative blood and fluid replacement and the trend of decreasing blood transfusion and increasing lactated Ringers solution and plasma expander was noticed. Supply of packed cell is required to improve the transfusion technique in future.
Anesthesia, General ; Blood Pressure ; Blood Transfusion ; Blood Volume ; Dextrans ; Humans ; Hypovolemia ; Korea ; Physiology ; Plasma ; Plastics ; Shock

Adult ; Aged ; Blood Volume ; physiology ; Female ; Glioma ; diagnosis ; physiopathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged

This paper is aimed to evaluate the accuracy and influence factors about quantitative assessment of valve regurgitation using flow convergence (FC) method with real-time tri-plane echocardiography. By an in vitro model made by ourselves we observed the areas of the FC of the regurgitant orifice under different diameters with the real-time tri-plane echocardiography. The effective regurgitant orifice areas (EROA) and the flow rate were calculated under different pressure gradients, instrument gain and color Doppler surveying range. The results were compared with the real size of the regurgitation orifice and flow rate. In 4mm, 6mm, and 8mm diameter of the regurgitant orifice, the instrument gain and color Doppler surveying rage have not significant influence on the measurement result of flow rate (P = 0.384, P = 0.903). But the measurement result of flow rate was increased following the pressure gradient augment (P = 0.00). While in the regurgitant orifice with diameter 2mm the measurement result of flow rate was influenced by the instrument gain but was not influenced by the pressure gradient or color Doppler surveying range (P = 0.55, P = 0.39). The measurement result of EROA was correlated well with the real regurgitant orifice area (r = 0.99). Using FC method with real-time tri-plane echocardiography to quantitatively assess the valvular regurgitation is simple and feasible. But it should be noted that the pressure gradient and diameter of regurgitant orifice have shown their influence on the results.
Blood Flow Velocity ; physiology ; Blood Volume ; physiology ; Computer Simulation ; Echocardiography, Three-Dimensional ; methods ; Heart Valve Diseases ; diagnostic imaging ; physiopathology ; Humans ; Image Interpretation, Computer-Assisted ; methods ; Models, Cardiovascular

OBJECTIVETo analyze the changes of cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen utilization (CMRO2) and oxygen extraction fraction (OEF) with age.

METHODSThe PET images of 7 young (21.0-/+1 years old) and 7 aged volunteers (60.9-/+4.7 years old) were analyzed to identify the areas where CBF, CBV, CMRO2, OEF had significant differences with age. The images were anatomically normalized by statistical parametric mapping (SPM2). A voxel by voxel calculation was performed to obtain the slope with age. Voxels which had statistically significant differences (P<0.05) with age were shown both on global and ROIs brain images.

RESULTSThe CBF decreased with age as was consistent with previous reports. The age-related changes in CBV and CMRO2 were similar to CBF, but OEF increased with age.

CONCLUSIONCBF, CBV and CMRO2 generally decline with age. The increase in OEF with age suggests a greater reduction in CBF than in CMRO2. The most significant decreases of CBF and CMRO2 occur in the convexity of the frontal cortex and inferior parietal cortex in all the functional images, while in the white matter, the influence of age is minimal.

Age Factors ; Aged ; Aging ; metabolism ; physiology ; Blood Volume ; physiology ; Brain ; blood supply ; diagnostic imaging ; Cerebrovascular Circulation ; physiology ; Female ; Humans ; Male ; Middle Aged ; Oxygen Consumption ; physiology ; Positron-Emission Tomography ; methods ; Reference Values ; Regional Blood Flow ; Young Adult

BACKGROUNDEvaluating the hemodynamic status and predicting fluid responsiveness are important in critical ultrasound assessment of shock patients. Transthoracic echocardiography with noninvasive diagnostic parameters allows the assessment of volume responsiveness. This study aimed to assess the hemodynamic changes in the liver and systemic hemodynamic changes during fluid challenge and during passive leg raising (PLR) by measuring hepatic venous flow (HVF) velocity.

METHODSThis is an open-label study in a tertiary teaching hospital. Shock patients with hypoperfusion who required fluid challenge were selected for the study. Patients <18 years old and those with contraindications to PLR were excluded from the study. Baseline values were measured, PLR tests were performed, and 500 ml of saline was infused over 30 min. Parameters associated with cardiac output (CO) in the left ventricular outflow tract were measured using the Doppler method. In addition, HVF velocity and right ventricular function parameters were determined.

RESULTSMiddle hepatic venous (MHV) S-wave velocity was positively correlated in all patients with CO at baseline (r = 0.706, P< 0.01) and after volume expansion (r = 0.524, P= 0.003). CO was also significantly correlated with MHV S-wave velocity in responders (r = 0.608, P< 0.01). During PLR, however, hepatic venous S-wave velocity did not correlate with CO. For the parameter ΔMHV D (increase in change in MHV D-wave velocity after volume expansion), defined as (MHV DafterVE - MHV DBaseline)/MHV DBaseline× 100%, >21% indicated no fluid responsiveness, with a sensitivity of 100%, a specificity of 71.2%, and an area under the receiver operating characteristic curve of 0.918.

CONCLUSIONSDuring fluid expansion, hepatic venous S-wave velocity can be used to monitor CO, whether or not it is increasing. ΔMHV D ≥21% indicated a lack of fluid responsiveness, thus helping to decide when to stop infusions.

Aged ; Blood Pressure ; physiology ; Cardiac Output ; physiology ; Echocardiography ; Female ; Fluid Therapy ; Hemodynamics ; physiology ; Hepatic Veins ; physiology ; Humans ; Male ; Middle Aged ; Monitoring, Physiologic ; methods ; Portal Vein ; physiology ; ROC Curve ; Shock ; physiopathology ; Stroke Volume ; physiology

OBJECTIVETo study the expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells (PBMCs) in children with bronchial asthma, as well as their roles in the pathogenesis of asthma.

METHODSThirty children with acute exacerbation of bronchial asthma were enrolled as the asthma group, and 20 healthy children were enrolled as the control group. RT-PCR and Western blot were used to measure the mRNA and protein expression levels of PI3K, NF-κB, and STAT1 in PBMCs. A spirometer was used to compare the pulmonary function between the two groups. The correlations between the mRNA expression of PI3K, NF-κB, and STAT1 and pulmonary function in children with bronchial asthma were analyzed.

RESULTSThe asthma group had significantly higher mRNA and protein expression levels of PI3K, NF-κB, and STAT1 than the control group (P<0.05). Compared with the control group, the asthma group showed significant reductions in pulmonary function indices such as FEV1%, FEV1/FVC, and PEF% (P<0.05). In children with bronchial asthma, the mRNA expression levels of PI3K, NF-κB, and STAT1 were negatively correlated with FEV1%, FEV1/FVC, and PEF% (P<0.05).

CONCLUSIONSThe expression levels of PI3K, NF-κB, and STAT1 increase in children with asthma, and are negatively correlated with pulmonary function indices, suggesting that PI3K, NF-κB and STAT1 are involved in the development and progression of bronchial asthma in children.

Asthma ; blood ; etiology ; physiopathology ; Child ; Child, Preschool ; Female ; Forced Expiratory Volume ; Humans ; Leukocytes, Mononuclear ; chemistry ; Male ; NF-kappa B ; blood ; genetics ; physiology ; Phosphatidylinositol 3-Kinases ; blood ; genetics ; physiology ; RNA, Messenger ; analysis ; STAT1 Transcription Factor ; blood ; genetics ; physiology

OBJECTIVEThis study examined the levels of exhaled nitric oxide (eNO) and peripheral blood eosinophils (EOS) as well as the correlation between the two markers in children with bronchial asthma (AS),AS complicated by allergic rhinitis (AS/AR) and chronic cough variant asthma (CVA), in order to explore the value of eNOS detection in children with AS.

METHODSThe eNO level was measured using light-emitting electrochemical photometry in 12 children with AS, 29 children with AS/AR and 10 children with CVA. Peripheral blood EOS was counted by blood cell counter (Coulter JT). Forced expiratory volume in one second (FEV1) was assessed by lung function measurement. Thirty children without atopic disease and acute respiratory infection as well as without a family history of atopic diseasea served as the control group.

RESULTSThe levels of eNO and blood EOS in the AS, the AS/AR and the CVA groups were significantly higher than those in the control group (p<0.01). The AS/AR group showed increased levels of eNO (50.3 + or - 6.7 ppb) and EOS (5.9 + or -4.2 x 109 ) compared with the AS (30.5 + or - 8.8 ppb and 4.2 + or - 3.2 x 109 respectively) and the CVA groups (26.0 + or - 3.2 ppb and 3.7 + or - 6.9 x 109 respectively) (p<0.05). There were no significant differences in eNO and EOS levels between the AS and the CVA groups. The eNO level was positively correlated with the EOS level (r=0.51, p<0.05), but not with FEV1 (r=0.144, p>0.05) in the AS group.

CONCLUSIONSNO is highly expressed in children with symptoms of atopy and can reflect the levels of eosinophilic airway inflammation in children with AS.

Adolescent ; Asthma ; blood ; physiopathology ; Breath Tests ; Child ; Child, Preschool ; Eosinophils ; physiology ; Female ; Forced Expiratory Volume ; Humans ; Male ; Nitric Oxide ; metabolism

OBJECTIVETo compare the differences in stroke volume (SV) and stroke volume index (SI) between Han and Korean-Chinese and to investigate the correlated risk factors.

METHODSA total of 1 647 Han and 876 Korean-Chinese aged 10-80 years were investigated. SV, SI, cardiac output, cardiac output index, heart rate (HR), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI), and blood pressure were measured.

RESULTSSV/SI values in Korean-Chinese were lower than those in the Han of the same sex and age. Covariance analysis showed that, apart from the effect of sex, age and body mass index (BMI), the differences in SV and SI between the two cohorts were still significant (P<0.001). Multiple regression analysis revealed that the SV difference between the two ethnicities was affected (in descending order from a strong to weak correlation) by SVR, SVRI, HR, diastolic blood pressure, mean arterial pressure, BMI, and systolic blood pressure, while the SI difference was affected by SVR, SVRI, HR, mean arterial pressure, diastolic and systolic blood pressure, and BMI.

CONCLUSIONThe Fact that SV and SI in Korean-Chinese are lower than those in Han is related with higher SVR, HR and blood pressure in the Korean-Chinese.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Blood Pressure ; physiology ; Child ; Female ; Humans ; Male ; Middle Aged ; Stroke Volume ; physiology ; Young Adult